What are the differences between EQ Eqv and equal?
Two objects that are eq are both eqv and equal. Two objects that are eqv are equal, but not necessarily eq. Two objects that are equal are not necessarily eqv or eq. eq is sometimes called an identity comparison and equal is called an equality comparison.
What is a data type in racket?
4.1 Basic Types The most basic types in Typed Racket are those for primitive data, such as True and False for booleans, String for strings, and Char for characters.
How do you know if two things are equal in scheme?
Use the = predicate when you wish to test whether two numbers are equivalent. Use the eqv? predicate when you wish to test whether two non-numeric values are equivalent.
What does cond mean in Scheme?
Chapter: Conditionals in Scheme cond works by searching through its arguments in order. It finds the first argument whose first element returns #t when evaluated, and then evaluates and returns the second element of that argument. It does not go on to evaluate the rest of its arguments.
How do you write not equal to in Scheme?
The not operation always returns #t or #f. Since Scheme doesn’t have a numeric “not equals” operator (like the != operator in C/Java/Python), we have to combine not and = in order to evaluate “not equals”. The Scheme interpreter runs in a Read-Evaluate-Print Loop (REPL).
What is an unbound identifier?
An identifier without a binding is called an unbound identifier.
How do you use if statements in schemes?
In Scheme, there’s no need for both an if statement and an if-like ternary expression operator, because if “statements” are expressions. Note that even though every expression returns a value, not all values are used–you can ignore the return value of an if expression.
What does nil mean in Scheme?
the empty list
Basically, nil in scheme is the empty list, so quoting an empty list gives you nil.
How do you define a struct?
A struct in the C programming language (and many derivatives) is a composite data type (or record) declaration that defines a physically grouped list of variables under one name in a block of memory, allowing the different variables to be accessed via a single pointer or by the struct declared name which returns the …
What is the meaning of equal in racket?
The equal? predicate follows the Racket semantics, extended to work with symbolic values. In particular, two values are equal? only when they are eq?, unless a more permissive notion of equal? is specified for a particular datatype. Examples: > ( equal? 1 #t) #f. > ( equal? 1 1.0)
What is the difference between EQ and EQV?
So very coarsely, eq? is pointer equality, eqv? is (atomic-)values-aware, equal? is also structure-aware (checks into its arguments recursively, so that finally (equal? ‘ (a) ‘ (a)) is required to be #t ), = is for numbers, string=? is for strings, and the details are in the Report. Show activity on this post.
What is the equal predicate in racket?
The equal? predicate follows the Racket semantics, extended to work with symbolic values. In particular, two values are equal? only when they are eq?, unless a more permissive notion of equal? is specified for a particular datatype.
What is the difference between rosette and Racket’s EQ?
Rosette treats these transparent types as value types , while Racket does not. Racket’s eq? may therefore return #f when given two instances of such a transparent type, regardless of their contents.